Attachment for micrometers



June 22 1926. 1,589,462

' A. DE GHETTO ATTACHMENT FOR MICROMETERS v Filed Sept. 18, 1924 INVENTOR @4111 A6 an Patented June 22, 1926.

UNITED STATES ANSELM DE GHETTO, OF CLIFTON, NEW JERSEY.

ATTACHMENT FOB MICROMETERS.

Application filed September 18, 1924.

My invention relates to improvements in micrometer attachments.

An object of my invention is to provide a simple and convenient device which may be attached to a micrometer for the purpose of subdividing the divisions of the micrometer scale; a further object of my invention is to provide a simple and convenient detachable micrometer scale; and a further object of my invention is to provide asimple and convenient device for subdividing and reading the divisions of a scale I accomplish these objects by the device illustrated in the accompanying drawings,

7 in which,

Figure 1 is a view of a micrometer provided with my improved attachment.

Figure 2 is a plan view of the attachment removed from the micrometer.

Figure 3 is a view of the device with the cover plate removed.

Figure 4. is a side view of the interior of device with the side plate removed, and

Figure 5 is a view of the supporting shaft.

Similar characters of reference refer to similar parts throughout the several views.

My improved attachment is designed to be applied toa micrometer of the usual type, one form of which is illustrated in Figure 1 and includes a frame 1 having an anvil 2 at one end with which the end of the spindle 3 coordinates. This spindle is carried in a barrel 4 provided with a longitudinal series of graduations 5 with which annular graduations 6 on a thimble 7 cooperate all of which is well understood in the art. By turning the thimble 7 the spindle 3 is moved toward or from the anvil and the distance between the end of spindle 3 and the anvil 2 is indicated on the longitudinal and annular scales.

It becomes desirable attimes to further divide the graduations of the annular scale 6 and I accomplish this subdivision by means of my improved attachment.

I provide a dial 8 having a hand or indicator 9 adapted to make one complete revolution for each subdivsion of the annular scale 6 as is hereinafter more particularly described and this dial 8 is subdivided as may be desired so that minute subdivisions of the annular graduations 6 may be readily and accurately determined.

The hand or indicator 9 is mounted on a shaft 10 which carries a geared pinion Serial No. 738,367.

11. A gear 12 engages the pinion 11. and is carried on a shaft 13 which also carries a pinion 14 which engages the geared drive wheel 15 carried on a hollow shaft 16 adapted to be keyed on the thimble 7 by means of a set screw 16 These geared wheels 11, 12, 14 and 15 are so proportioned that one complete revolution of the indicator 9 will mark one graduation 'of the annular scale 6 carried by the thimble 7.

- My device is preferably carried between two plates 17, 18 and is protected by a side casing as may be desired. The plate 17 and 18 may be secured by means of bolts 19, 20 or the like.

A supporting shaft 21 is provided with jaws 22 to engage the micrometer scale and to accurately position my attachment thereon. A set screw 23 is provided to securely hold the aws 22 on the frame 1.

Having thus described my invention, what I claim is:

1. In a device of the character described having a rotatable shaft, a casing, a train of gears in said casing having a shaft, one of said gears having a hollow shaft, a dial on said casing, a pointer on the shaft of said gear train, and screw means to operatively connect said pointer and said hollow shaft to said rotatable shaft.

2. In a device of the character described a casing, a. gear in said casing having a hollow shaft, a second gear in said casing having a shaft extending beyond said casing a pointer fixed to said shaft outside said casing, a dial on said casing to cooperate with said pointer, means operatively connecting said gears, a rotatable shaft and means on said hollow shaft for releasably securing the same to said rotatable shaft.

3. In a device of the character described having a casing provided with aligned openings in said casing, a gear having a hollow shaft mounted in said openings, there being other openings in said casing, a shaft having jaws thereon mounted in said other openings, a rotatable shaft having an arm attached thereto, said jaws adapted to fit over said arm, and means whereby the rotatable shaft may be locked in said hollow shaft.

In testimony whereof, I have signed my name to this specification this fifth day of September, 1924:.

ANSELM DE GHETTO. 

